So what's going on with these people? I'll sometimes see two people with exactly the same name, except one has a number 1 in brackets behind his name. They both seem to be actively playing because I'll regularly get killed by either one.
that is because whom ever is playing has a guest signed in. you can see up to 4 poeple with the "same name" just with numbers after the names.
It's when you play split screen, I haven't tried it yet but it was alot of fun in Halo 3 so I guess it will be fun in this game too.
I do it with my brother when we get to use the big TV but on the 22" (or whatever it is) it's a bit too difficult to play. But yeah, as other's said. It's splitscreen. On some games you can play splitscreen over Xbox LIVE but the second controller doesn't need a Gold Account, they just need to sign in as guest. Before you press 'Quick Match', turn on a second controller and press Y (I think), you will be able to sign in a guest to play with. Real bugger when they sometimes get put on the other team but that's only happened once that I can remember. Real big props to the dev for putting this in. Made the game an instant sale.
In any game if you see the same exact name twice with the 2ns name having a number and some of the name cut off due to the number it is a split screen. Although if the second player had the own account there would be no number and no way to tell they are split screening. Me and my brother used to do this is Gears.